SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '530d3929154f694411607dacf28dbd2dc19919f44ef1710b494a01d06c420c15' 
  AND token = 'AVvlx1fOp6qkb5KQbIONCc2S01isGrk7XNf6wtAJHFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}